The present invention relates to collecting geographic data and more particularly, the present invention relates to a process and system that determines the positions of cellular phones, or other types of wireless phones, matches the positions of the cellular phones to positions of roads in a geographic area, and uses the results of the matching for updating or refining a geographic database, traffic monitoring, or for other purposes.
Geographic databases have various uses. Geographic databases are used in in-vehicle navigation systems, personal computers, networked computing environments, and various other kinds of platforms, as well as on the Internet. Geographic databases are used with various kinds of applications to provide various functions including map display, route calculation, route guidance, truck fleet deployment, traffic control, traffic monitoring, electronic yellow pages, roadside assistance, emergency services, and so on.
In order to provide these kinds of functions, a geographic database includes data that represent geographic features in a covered geographic region. Geographic databases include details about represented geographic features, such as the geographic coordinates of roads in a geographic region, speed limits along the road segments, locations of stop lights, turn restrictions at intersections of roads, address ranges, street names, and so on. Geographic databases may also include information about points of interest in covered regions. Points of interest may include restaurants, hotels, airports, gas stations, stadiums, police stations, and so on.
Collecting information for a geographic database is a significant task. Not only is the initial collection of data a significant undertaking, but a geographic database needs to be updated on a regular basis. For example, new streets are constructed, street names change, traffic lights are installed, and turn restrictions are added to existing roads. Also, new levels of detail may be added about geographic features that are already represented in an existing geographic database. For example, an existing geographic database for roads may be enhanced with information about lane widths, shoulder sizes, lane barriers, address ranges, sidewalks, bicycles paths, etc. Thus, there exists a need to continue to collect information for a geographic database.
One method for collecting data for a geographic database is described in European Patent Application No. EP 0 921 509. According to one embodiment described in EP 0 921 509, navigation systems installed in a plurality of vehicles are used as probes to collect geographic data as the vehicles are driven in a geographic region. These navigation systems may also provide navigation-related features to the drivers and/or passengers of the vehicles in which they are installed or alternatively the navigation systems may serve only to collect geographic data as the vehicles in which they are installed are driven. The geographic data collected by the plurality of vehicles are gathered together, analyzed, and used to update or refine a master geographic database. Copies of the master geographic database, or database products derived from the master copy, can then be distributed back to the plurality of vehicles and used in the navigation systems installed in the plurality of vehicles.
The embodiments described in EP 0 921 509 can afford advantages. However, there is still room for improvement. Accordingly, there exists a need to provide an improved method and system for collecting data for a geographic database.
There also exists a separate need to collect traffic information. Collection of traffic information is important for many purposes. For example, traffic information is used by commuters on a daily basis. Various methods have been used to collect traffic information. These methods have included direct observation, sensors embedded in the roads or located alongside roads, and other means. Although prior methods of collecting traffic information have been adequate, there exists room for improvement. For example, traffic information could be collected less expensively. Also, prior methods of traffic information collection have focused on only certain roads, typically the roads with the highest volumes of traffic. It would be beneficial to collect traffic information for more roads.
To address these and other objectives, the present invention comprises a method and system that matches the positions of one or more cellular phones, or other types of wireless phones, to data indicating the locations of roads in a geographic area to derive data about phones located in vehicles traveling along the roads. The data about phones located in vehicles traveling along the roads are used for updating or refining a geographic database, traffic monitoring and/or reporting, or for other purposes.